Trajectory Tracking Control Research Of The Large Airship

The large airship is a kind of high altitude aircraft relying on static buoyancy,with the characteristics of low energy consumption,high carrying capacity and long duration.It can be used to monitor ground(eg.forest fire monitoring),communication relay or larce load transportation,etc.And it have many advantages in both the military and civilian fields.The airship must ensure a stable and controllable posture and position.So the stability analysis and trajectory tracking controller design are the basic part of airship.However,the airship is hard to control,with the characteristics of large volume,low speed and complex service environment.Considering such situation,this article established a reasonable nathematical model,and researched on the dynamic analysis and stability evaluation based on the model.Then the article carried out on the airship trajectory tracking controller design on the basis of the theory of trajectory linearization control(TLC).In this paper,main work is as follows:1.Large airship force analysis and dynamic modeling.Based on the coordinate system,consider ing the static air,fluid power,control power and converting them into same coordinate system,this article established the airship six degrees of freedom nonlinear dynamics model and deduced the general simplified expressions.It lay a foundation for stability analysis and trajectory tracking in the next step.2.Large airship stability assessment.By using the small disturbance method,small perturbation equation was deduced from the airship longitudinal and lateral direction.And then combined with the theory analysis and computer simulation method,respectively from two kinds of motions including the horizontal lateral and longitudinal course,this paper evaluated the stability performance and stability control law through three aspects:stability of the airship,manipulation reaction and the dynamic model.3.Large airship trajectory tracking control design.The tactics of trajectory tracking controllers for flully-actuated airship was put forward based on the six degrees freedom mathematical model of airship.The tactics divided whole system into four control loops,each control loop adopted the theory of trajectory linearization control(TLC)to carry on the trajectory tracking design.This method avoided the difficulty of the directly inverse of the whole system.4.The GUI design of large airship trajectory tracking process.Through Matlab/GUI,this paper designed a graphical user interface.Users can directly enter the airship actual structure parameters by simple interface.Then users can observe the corresponding stability performance analysis results and the trajectory tracking control simulation results,This interface made users testing airship structure parameter and trajectory tracking design results more convenient.